King's spokesperson, Crystal Canney, says the ads are bolstering the campaign of Republican Charlie Summers with no disclosure about who paid for them.

The Angus King for U.S. Senate campaign is calling on Republican candidate Charlie Summers to take off the air recent negative television ads targeting King that have flooded Maine in recent weeks. King's spokesperson, Crystal Canney, says the ads are bolstering Summers with no disclosure about who paid for them.

"He is benefiting from these negative partisan ads out of Washington, which are misleading and deceptive, and we'd like to see him take that step," Canney says.

Canney says the Republican National Senatorial Committee - or RNSC - and the U.S. Chamber of Commerce have spent more than $2 million on the ads. She says one of them references King's former wind company and claims he received a loan guarantee when he did not.

A "truth test" by The Portland Press Herald rated the entire ad mostly false. The Summers' campaign was unable to be immediately reached for comment.